Electrical control circuit

摘要

The present invention concerns electrical control circuits which are particularly applicable to use and controlling the starting of electric motors. The invention thus provides a sensing and switching circuit capable of automatically to bring into and out of operation the start winding of an electric motor at appropriate motor speeds. Appropriate means sense a voltage or current level and a trigger response to the sensed value to supply firing pulses to the gate of a triac. The trigger element is preferably an M.O.S. integrated circuit multivibrator.